Assistive technologies are software or hardware products that make software applications or operating systems accessible to individuals with a range of disabilities, such as impaired mobility, sight, hearing, etc. Examples of assistive technologies include magnifiers, screen readers, and Braille displays. These products use a variety of data interception techniques throughout the operating system in order to operate. Generally, assistive technologies intercept graphics primitive function calls at the display driver interface (DDI) level and use the operating system kernel state to build off-screen models. Such techniques often cause system instability and crashes.